JPH07245300A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) [Summary] [Objective] For the coverage of contact holes of 0.5 μm or less, improve the coverage of the BW film from the selection of the glue layer, the hole shape, and the W growth conditions. [Structure] The method has a step of sequentially forming a titanium film 3, a titanium nitride film (glue layer) 4, and a tungsten film 8 on a semiconductor substrate 1 having an insulating film 2 with a contact hole formed on its surface. , The titanium nitride film forming temperature is 400
℃ or more, the deposition power of the titanium nitride film is 10 W / c
m ² or more, and the nitrogen flow rate ratio during film formation is 60% or more. In addition, titanium nitride is formed by nitriding titanium with RTA. Further, the deposition temperature of the tungsten film 4G as the glue layer is 400 ° C. or higher, the gas pressure during the deposition is 7 mTorr or higher, and the deposition power is 2 to 4 W / cm.
² or more

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method for forming a blanket-tungsten (BW) wiring film of a semiconductor device having a contact hole of 0.5 .mu.m or less, and a contact hole or via of 1.0 .mu.m or less. (V
(IA) A manufacturing method for forming a tungsten-plug (W-PLUG) by etching back a B-W film of a semiconductor device having a hole.

[0002]

2. Description of the Related Art In a conventional semiconductor device, aluminum (Al) and its alloy have been used as a wiring material. Therefore, the conditions required for a barrier metal are that a mutual reaction with Al is slow and a barrier property is improved. There has been a demand for a film that can be easily oxygen (O ₂ ) stuffed.
As a film in which O ₂ stuffing is likely to occur, a film having a small grain, a low density, a high O ₂ concentration, a high specific resistance, and a main orientation of (111) has been required.

22 (A) to 22 (C) are explanatory views of the prior art. FIG. 22 (A) shows the basic structure, 1 is silicon (S
i) substrate, 2 is an interlayer insulating film, 3 is a titanium (Ti) film, 4
Is a titanium nitride (TiN) film, 5 is an Al wiring, and 6 is an O atom.

FIG. 22B is an enlarged view of the TiN film 4.
N film 4 has high resistance, small grains, low density, (1
11) In the case of orientation, O ₂ stuffing is easy and Al
The barrier property against is excellent.

In FIG. 22C, when the barrier property of the TiN film 4 is poor, Al / TiN interdiffuses to generate an Al spike 7 on the Si substrate. However, the contact hole is made finer to 0.5 μm or less, and wiring is formed by the BW film (FIG. 23), or is formed by etching back the BW film in the contact hole or the via hole to 1.0 μm or less. W-plug technology (FIG. 24) has become necessary.

FIG. 23 is an explanatory view of wiring by a BW film.
8 is a B-W film. 24 (A) and 24 (B) are explanatory views of the W-plug technology. In FIG. 24 (A), when the base is W, in (B), the base is A.
An example of the case of 1 is shown, and the reference numeral 8P is a W-plug.

[0007]

However, when the barrier metal, which has been conventionally used for Al wiring, is used in the B-W wiring or W-plug technology by the same film forming method, it is difficult to form nuclei during W growth ( It has been found that erosion due to tungsten hexafluoride (WF ₆ ) occurs, causing junction leakage and increase in contact resistance (FIG. 26).

FIGS. 25A and 25B are explanatory views of nucleation during growth of the BW film. FIG. 25 (A) shows a state in which WF ₆ flies to the TiN film O ₂ stuffed on the surface and W nuclei are formed, and FIG. 25 (B) shows the TiN film (1) and O ₂ stuffed easily by O ₂ stuffing. TiN easily stuffed
Using the film (2) as a parameter, the relationship between the growth time and the growth film thickness is shown. It can be seen from the figure that the growth rate decreases when O ₂ stuffing is performed.

FIG. 26 shows Si during the growth of the BW film.
It is an explanatory view of erosion of WF ₆ to a substrate. As shown in the schematic diagram, WF ₆ erodes the Si substrate from the grain boundary of the TiN film, increases the contact resistance, or causes leakage of the junction formed in the substrate.

Further, when the TiN / Ti film is formed by a normal sputtering apparatus, if Ti under TiN is exposed, Ti
Is exposed to WF ₆ and is etched, and the TiN film and W thin film are peeled off (Fig. 2).
7).

27 (A) to 27 (C) show that the Ti film is exposed and the WF
It is explanatory drawing of the problem by being exposed to ₆ . FIG. 27
(A) holds the edge of the Si substrate (wafer) 1 with the clamp ring 9 during the TiN film formation, but due to the center deviation due to the tolerance of the equipment, the TiN film under Exposed Ti film, exposed directly to WF ₆ ,
As shown in FIG. 27 (C), the Ti film is eroded, and the TiN film and the W film deposited on the TiN film are peeled off.

As the glue layer (adhesion layer), TiN is used.
Besides, W can be considered. Further, it is known that the requirement required for W is similar to that of TiN (FIG. 28).
FIGS. 28A and 28B are explanatory views when the glue layer is a W film.

FIG. 28 (A) shows the case where the W film has a small grain size, low density and high resistance. In this case, WF ₆
Erosion becomes a problem. FIG. 28B shows the case where the grain size is large, the density is high, and the resistance is low. In this case, W nuclei are easily formed and WF ₆ erosion can be suppressed.

However, when W is selected as the glue layer, W in the W wiring forming step, etch back step, etc.
In the etching step, there was a problem that the selection ratio between W and the underlying insulating film (oxide film type) or the Si substrate could not be obtained (FIG. 29).

FIGS. 29 (A) and 29 (B) are views for explaining problems in patterning when the glue layer is a W film. Figure 2
9 (A), the glue layer W film 4G and the B-W wiring 8 are formed so as to cover the steps of the insulating film [phosphorus silicate glass (BPSG) film containing boron] 2 formed on the Si substrate 1. Then
A patterned photoresist film 10 is formed thereon.

In FIG. 29B, the glue layer W film 4G and the B-W wiring 9 are formed by low temperature etching using NF _3.
If patterned, the Si substrate below the step will be etched.

In this case, the etching selection ratio is BPSG.
/ W to 1 and Si / W to 3. Further, in a semiconductor device having a contact hole of 0.4 μm or less, it has been experimentally clarified that the extension of the conventional example does not provide sufficient step coverage of the contact hole even with the BW film. Therefore, some improvement is needed (Fig. 30).

FIGS. 30 (A) and 30 (B) are explanatory views of problems of the BW wiring in the contact hole of 0.4 μm or less. FIG. 30 (A) shows a contact hole of 0.5 μm or more, and FIG. 30 (B) shows a contact hole of 0.4 μm or less. The step coverage is poor and the BW film cannot fill the contact hole. Shows the state.

An object of the present invention is to improve the coverage of the BW film from the selection of the glue layer, the hole shape and the W growth conditions.

[0020]

[Means for Solving the Problems] 1) A titanium film (3) and a nitride film are formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is formed. A method for manufacturing a semiconductor device, which comprises a step of sequentially forming a titanium film (4) and a tungsten film (8), and a film forming temperature of the titanium nitride film (4) is 400 ° C. or higher, or 2) a contact hole is formed. It has a step of sequentially forming a titanium film (3), a titanium nitride film (4), and a tungsten film (8) on a semiconductor substrate (1) on the surface of which the formed insulating film (2) has been deposited. , The deposition power of the titanium nitride film (4) is 10 W / cm ²
The method for manufacturing a semiconductor device as described above, or 3) a titanium film (3) and a titanium nitride film (4) on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is deposited. And a tungsten film (8) are sequentially formed, and the nitrogen flow rate ratio when the titanium nitride film (4) is formed is 6
0% or more of the semiconductor device manufacturing method, or 4) a titanium film (3) and a titanium nitride film (3) on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is deposited. 4) and a tungsten film (8) are sequentially formed, and a method for manufacturing a semiconductor device in which the titanium nitride film (4) is formed by a bias sputtering method, or 5) an insulating film in which a contact hole is formed The method includes a step of sequentially forming a titanium film (3), a titanium nitride film (4), and a tungsten film (8) on a semiconductor substrate (1) having a surface (2) deposited thereon. A method for manufacturing a semiconductor device in which (4) is formed by a collimated sputtering method, or 6) a titanium film is formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is deposited. (3), a titanium nitride film (4) and a tungsten film (8) are sequentially formed. , A method of manufacturing a semiconductor device in which the titanium nitride film (4) is formed by a wide gap sputtering method in which the gap between the target and the substrate to be grown is expanded to 100 mm or more, or 7) an insulating film (where a contact hole is formed ( 2) has a step of sequentially forming a titanium film (3), a titanium nitride film (4), and a tungsten film (8) on a semiconductor substrate (1) having a surface coated with the titanium nitride film ( 4) A method of manufacturing a semiconductor device in which 4) is formed by a vapor deposition (CVD) method, or 8) A glue is formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is deposited. 9. A method for manufacturing a semiconductor device, which comprises a step of sequentially forming a layer tungsten film (4G) and a tungsten film (8), and a film forming temperature of the glue layer tungsten film (4G) is 400 ° C. or higher. ) Insulating film with contact holes (2) There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) deposited on the surface, and forming the glue layer tungsten film (4G). A method for manufacturing a semiconductor device in which the gas pressure is 7 mTorr or more, or 10) a tungsten film for glue layer is formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is deposited. (4G) and a tungsten film (8) are sequentially formed, and a method of manufacturing a semiconductor device, wherein the film forming power of the glue layer tungsten film (4G) is ² to 4 W / cm ² or more, or ) There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) on the surface of which an insulating film (2) having a contact hole is formed. , Deposition of the glue layer tungsten film (4G) A method for manufacturing a semiconductor device, which is performed by the method according to claim 4 or 6, or 12) a glue layer (4) is formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having contact holes is formed. And a tungsten film (8) are sequentially formed, the tungsten film (8) is patterned, and then the semiconductor substrate
(1) A method of manufacturing a semiconductor device in which the glue layer (4) is patterned using a reaction gas having a higher etching rate than that of (1), or 13) the glue layer (4) is made of titanium as the lower layer and titanium nitride as the upper layer. 12) The method for manufacturing a semiconductor device according to 12) above, or 14) the glue layer (4) is formed on the semiconductor substrate (1) with the titanium film completely covered with the titanium film. 8) The method for manufacturing a semiconductor device as described in 13) above, or 15) a glue layer (4) is formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having contact holes is formed. ) And a tungsten film (8) are formed in order, and the tungsten film (8)
Etching back to form a tungsten-plug (9P) in the contact hole, 1) to 14) above
16) A method for manufacturing a semiconductor device using the described method, or 16) A glue layer (4) and a tungsten film (8) are formed on a semiconductor substrate (1) on the surface of which an insulating film (2) having contact holes is formed. ) Are sequentially formed and the glue layer (4) nitrides the surface of the titanium film (3) by a rapid heating method, or 17) the titanium film (3) is formed. The method for manufacturing a semiconductor device according to 16) above, wherein the film is formed by a collimated sputtering method, or 18) the titanium film (3) is formed by a wide gap sputtering method in which the gap between the target and the substrate to be grown is expanded to 100 mm or more. In the method of manufacturing a semiconductor device according to 16) described above, or 19) in the above 1) to 18), a film containing at least a phosphosilicate glass film in its laminated structure is used for the insulating film (2),
750-85 for the coating before contact hole formation
20) In the method for manufacturing a semiconductor device in which heat treatment is performed at 0 ° C., or 20) in the above 1) to 18), a film containing at least a phosphosilicate glass film in its laminated structure is used as the insulating film (2),
21. A method for manufacturing a semiconductor device using isotropic etching and anisotropic etching for forming the contact hole, or 21) in the above 1) to 20),
This is accomplished by a method for manufacturing a semiconductor device, in which (8) is deposited under the surface reaction rate-determining condition.

[0021]

The present invention considers the following as the requirements for the glue layer of B-W are the ease of nucleation and the resistance to erosion of WF ₆ , and the solution thereof is given below. I focused on it.

FIGS. 1 (A) to 1 (D) are explanatory views of characteristic examples of the present invention. FIG. 1 (A) is an illustration of a film that facilitates nucleation. From the experimental results of the present inventor, it was found that the conditions of the glue layer where the nucleation of W is easy are as follows.

1) Large grains 2) High density 3) Low O ₂ concentration 4) Low specific resistance 5) (200) Strong orientation (in the case of TiN) Also, since the grain size is large, the infiltration of WF ₆ Can also be suppressed.

The present invention improves the film forming conditions of the glue layer and the conditions of the film forming apparatus so that such conditions are satisfied. Further, as a method of obtaining the selection ratio with the underlying insulating film or the Si substrate at the time of etching the W wiring and at the time of etching back the W-plug formation, as the glue layer, a film having a selective ratio with the underlying layer at the time of etching is selected. (Figs. 1 (B)-(D)).

FIGS. 1 (B) to 1 (D) are explanatory views of the patterning of the BW wiring according to the present invention. FIG. 1B shows a TiN / Ti film used as a glue layer in the BW wiring.
The etching selection ratio between Si and the glue layer can be obtained. In FIG. 1 (C), the B-W film 8 is etched by low temperature etching using NF ₃ , and then FIG.
In (D), the TiN / Ti film of the glue layer is etched by room temperature etching using Cl ₂ .

FIG. 2 is an explanatory diagram of a film forming method in which the Ti film is not affected by WF. In order to solve the peeling problem when using a TiN / Ti glue layer, as shown in the figure, Ti
Is not exposed during W growth.

Further, the improvement of the step coverage of 0.4 μm or less is that the TiN of the glue layer formed by ordinary film formation is used.
/ Ti overhang-shaped step coverage was confirmed, and attention was focused on improving the coverage of the glue layer. From the vertical contact hole shape (in the case of anisotropic etching) to the wine glass shape ( (For isotropic + anisotropic etching) (Fig. 3), the contact hole shape is improved, and the BW film growth condition is the surface reaction rate-determining condition. The one that improves the coverage of itself (Fig. 4), and its combination.

In the present invention, the nucleation during growth of the BW film in the contact hole of 0.5 μm or less is stabilized,
In order to prevent erosion of WF ₆ , the following is required as the film quality of the glue layer in the case of TiN / Ti structure.

1) Large grain 2) High density 3) Low O ₂ concentration 4) Low specific resistance 5) (200) Strong orientation (in the case of TiN) As a concrete realization method, a) film formation temperature Is 400 ° C. or higher (FIG. 5) b) Increases input power (FIG. 6) c) Increases N ₂ flow rate ratio (FIG. 7) d) Performs bias sputtering e) Performs collimated sputtering f) Wide gap Sputtering is carried out. G) CVD method is used (see d) to g) above).

[0030]

[Table 1] Resistivity Main Alignment Normal Sputtering- (111) Bias Sputtering Low (200) Collimator used Low (200) Wide gap low (200) Depends on CVD method (200) Is a comparison with respect to the spatter.

When the sputtered W film is used as a glue layer, a) film forming temperature is 400 ° C. or higher (FIG. 8) b) film forming pressure is high pressure (FIG. 9) c) input power Can be achieved by using the above methods d) to f) in the case of TiN / Ti.

Further, the wiring forming film and the plug forming film W
Different from the above, and by using TiN as the glue layer, which has an etching selection ratio with the underlying insulating film or the Si substrate, excellent wiring formation and plug formation can be performed (FIG. 1).

In the TiN / Ti structure, the hole diameter of the TiN clamp ring is made larger than the hole diameter of the Ti clamp ring to prevent exposure of Ti during W growth.
It is possible to prevent peeling of TiN and W (FIG. 2). Further, in order to improve the coverage of the BW film at 0.4 μm or less, in order to improve the coverage of the glue layer, the coverage of the glue layer is improved (overhang). Of the above), a) film formation by collimated sputtering is performed (Fig. 1).
1, 12) b) Wide gap sputtering is performed (FIG. 13) c) CVD method is used. D) Ti is used as a glue layer and RTA (Rap) is used.
nitriding by id Therm-al Annealing (FIG. 14) e) nitriding Ti by collimation sputtering by RTA (FIGS. 11 and 14) f) nitriding wide gap Ti (FIGS. 11, 13 and 13).
14) FIGS. 11 (A) and 11 (B) are explanatory views of coverage, (B) shows film formation by normal sputtering, and (A) shows film formation by collimated sputtering, and the overhang after film formation is small. .

12A and 12B are a plan view of the collimated sputtering apparatus and a plan view of the collimator. FIG. 13 is a plan view of the wide-gap sputtering apparatus. The distance between the target and the wafer is 100 to 100 mm compared to the normal 40 to 70 mm.
To 700 mm.

14 (A) to 14 (C) are explanatory views of the formation of a glue layer using nitriding by RTA, and FIG. 14 (A) is a cross-sectional view when TiN is covered by covering the contact hole.
Overhang is large. On the other hand, when the Ti film 3 is sputtered as shown in (B) and (C), the overhang is small, and nitriding by RTA is performed in that state.

In order to improve the contact hole shape, a) a heat treatment is performed after the contact hole is opened so that the upper part of the hole is rounded (FIG. 15). B) The contact hole shape is isotropic + anisotropic. In order to improve the coverage of the B-W film itself, there is a method of setting the growth condition of the B-W film as a reaction rate-determining condition (Fig. 4).

By using these methods in combination, 0.
A wiring coverage similar to that of a 5 μm rule generation LSI is realized. FIG. 15 is a diagram for explaining the rounding of the shoulder due to heat treatment of the contact hole. (A) and (B) show the case without heat treatment,
(C) and (D) are with heat treatment and the overhang is small.

[0038]

【Example】

(Embodiment 1) (Refer to FIG. 16) The first layer wiring of 64M DRAM will be described as an example. Contact holes are phosphorus silicate glass containing boron (BPSG) 2A
/ (Non-doped silicate glass (NSG) 2B laminated film
(Film thickness is ~ 300 nm / 300 nm) about 0.4-0.
A hole having a diameter of 5 μm is formed. After opening the contact holes, compensating ion implantation (II) is implanted into the n ⁺ / p ⁺ regions through the respective mask steps to remove the resist, and then annealing for activation is performed at a temperature of about 800 ° C. This compensation I
The step I is not necessary, but the last annealing step is preferable because it rounds the shoulder of the BPSG film above the contact hole.

Next, the glue layer T
An iN (50 nm) film 4 / Ti (20 nm) film 3 is formed. At this time, the requirements for the quality of the glue layer TiN film 4 are 1) large grains 2) high density 3) low O ₂ concentration 4) low specific resistance 5) (200) strong orientation (in the case of TiN) is there.

In order to carry out this concretely, if the TiN film forming conditions are set as follows, film forming temperature: 500 ° C. input power: 10 W / cm ² N ₂ flow rate: 80% A film satisfying 1) to 5) can be formed.

Further, as a film forming method for emphasizing the effects of 1) to 5), a) bias sputtering: a bias of DC or RF of −100 V to the substrate.
Apply in the range of -600V.

B) Collimated Sputtering A collimator with an aspect ratio of 1: 1 is inserted between the target and the wafer to carry out deposition.

C) Wide Gap Sputtering It is carried out by forming a film with a distance between the target and the wafer in the range of 100 to 500 mm.

D) Film Formation by Vapor Deposition (CVD) Method Titanium tetrachloride (TiCl ₄ ) is used as a source gas by the CVD method.

On the glue layer thus grown, a CVD-W film having a thickness of 350 nm is blanket grown. (Example 2) (see FIG. 17) Next, a case where a W film having a thickness of 100 nm is used as a glue layer will be described. The requirements are 1) large grains 2) high density 3) low O ₂ concentration 4) low specific resistance.

In order to carry it out concretely, the film forming conditions for W are as follows: Film forming temperature: 500 ° C. Discharge pressure: 7 mTorr Input power: 3 W / cm ^{2 Even in} ordinary sputtering, the above 1) A film satisfying ~ 4) can be formed.

Further, as a film forming method for emphasizing the effects of 1) to 4), the methods of a) to c) described in the TiN film forming can be applied. (Embodiment 3) (See FIGS. 1B to 1D) A W wiring forming process will be described. When etching the W / TiN / Ti laminated film formed in Example 1, first, W etching is performed by low temperature etching using NF ₃ (−30 to −60 ° C.). At this time, when dissimilar metals such as TiN according to the present invention are not used and sputtered W is used as the glue layer, the BPSG that is the base insulating film and the Si substrate exposed to the scribe line are etched by NF _3. As a result, a problem that a good pattern cannot be formed occurs. Here, by performing TiN / Ti etching with chlorine (Cl ₂ ) at room temperature after completion of W etching, it is possible to form a pattern while ensuring a sufficient selection ratio between the underlying insulating film and the Si substrate.

(Embodiment 4) (See FIG. 2) When a TiN / Ti laminated film is used as a glue layer forming method, if Ti under TiN is exposed, the Ti is Exposed to the source gas WF ₆ ,
It will be etched. Therefore, the inner diameter of the clamp ring of the sputtering apparatus, which is the glue layer film forming apparatus, must be set to the inner diameter for the TiN film> the inner diameter for the Ti film so that the upper layer TiN always covers Ti.

(Embodiment 5) (FIG. 18) The present invention can be applied not only to the B-W wiring but also to the W-plug. The example is given below.

CMOS LOGI of 0.35 μm rule
A C LSI is shown as an example. The via hole is a via hole of 1.0 μm or less formed in a laminated film (film thickness 0.9 to 1.1 μm) of the spin-on-glass (SOG) film 2C / NSG film 2A. After opening the contact hole, a TiN film 4 as a glue layer is formed with a film thickness of about 50 nm. The film forming conditions at this time may satisfy the same requirements as in Example 1. Further, as an application, in the case of forming the W-plug of the contact hole, the same applies when the glue layer is TiN / Ti. A B-W film is grown on the glue layer thus formed and etched back to form a W-plug. At the time of etch back, if TiN (via) or TiN / Ti (contact) is used as the glue layer, the etch back is stopped on TiN, and if W is used, the etch back is performed up to W. Become.

(Embodiment 6) (See FIG. 19) In a contact hole of 0.4 μm or less, BW
Even if wiring is used, the wiring coverage deteriorates due to the overhang shape of the glue layer. Therefore, it is necessary to improve the step coverage of the glue layer, paying particular attention to the overhang.

The first layer wiring of 256M DRAM is shown as an example. Contact holes are BPSG film 2B / NSG film 2A
Of the laminated film (thickness: ~ 300 nm / 300 nm) of about 0.
A hole having a diameter of 2 to 0.4 μm is opened. After opening the contact holes, Compensation II is injected into the n ⁺ / p ⁺ regions through the respective mask steps to remove the resist, and then annealing for activation is performed at a temperature of about 800 ° C. This Compensation II step is not necessary, but it is desirable to have it in the final annealing step because it rounds the B-PSG above the contact hole.

Next, TiN (50 nm) of the glue layer
The film 4 / Ti (20 nm) film 3 is formed. At this time, in order to improve the coverage of the glue layer, as film forming conditions, b), c), d) of Example 1, and further, e),
As a glue layer, Ti with less overhang than TiN is formed by normal sputtering to about 70 nm, and RTA
By annealing in an N ₂ atmosphere at about 600 to 700 ° C. for 20 to 60 seconds for nitriding.

F) In the above Ti film forming method, T
In order to improve the overhang of i, a collimated Ti film, a wide gap Ti film or the like is used.

Further, by improving the hole shape, it is possible to suppress the overhang shape even in ordinary TiN / Ti. As a method, besides the above heat treatment, the etching shape may be isotropic + anisotropic etching. As an isotropic formation method, BHF (Bu-) using a surfactant (50 to 200 ppm) was used.
federed HF; NH ₄ F: HF 6: 1 to 1
An etchant with a ratio of 0: 1), 200-300
There is a method of etching the BPSG film 2B having a thickness of 2 nm (see FIGS. 20A and 20B).

A 250 nm-thick CVD-W film is blanket grown on the TiN / Ti glue layer thus formed. g) Approach from W growth conditions is also possible (Fig. 2
1, Table 2).

Table 2 explains the W growth conditions (reaction rate and supply rate).

[0058]

[Table 2] Reaction rate controlled supply rate Growth temperature Low 〜 450 ℃ High 〜 475 ℃ WF ₆ Flow rate Large 〜 60 sccm Low 〜 30 sccm Coverage Good Bad Surface morphology Poor Good Surface morphology is acceptable and can be used with 256 DRAM.

Conventionally, the growth of the W wiring is controlled by the supply rate condition (the film forming temperature is about 460 to 480 ° C., and the WF ₆ flow rate is 2).
The surface morphology was prioritized at about 0 to 40 sccm). However, in the 256M DRAM, the film forming condition is about 440 to 460 ° C. and the WF ₆ flow rate is 50 to 70 s.
By setting ccm, the coverage is improved and the surface morphology is improved by reducing the film thickness.

This means that even when the W film is a glue layer, W- in a via hole of 0.5 μm or less is further observed.
It is common in the case of plug technology. Figure 21 is WF
Fig. ₆ is a diagram showing the relationship of the deposition rate with respect to the flow rate. The linear part of the proportional relationship is the supply-controlled region, and the saturation region of the deposition rate represented by the horizontal line is the reaction-controlled region.

[0061]

As described above, according to the present invention, the coverage of the blanket-tungsten (BW) film can be improved by the selection of the glue layer, the hole shape, and the W growth condition. Also, the W wiring according to the present invention
The formation of the W-plug has an effect on the stability of the device and future scaling, and can contribute to the performance improvement of the semiconductor device.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a characteristic example of the present invention.

FIG. 2 is an explanatory diagram of a film forming method in which Ti is not corroded.

FIG. 3 is an explanatory view of improving the shape of a contact hole.

FIG. 4 is an explanatory diagram of improvement of BW film growth conditions.

FIG. 5 is a diagram showing the film forming temperature dependence of the TiN film specific resistance.

FIG. 6 is a diagram showing the film forming pressure dependence of the TiN film specific resistance.

FIG. 7 is a diagram showing the nitrogen flow ratio dependence of the TiN film orientation.

FIG. 8 is a diagram showing the film formation temperature dependence of the W film specific resistance.

FIG. 9 is a diagram showing the film forming pressure dependence of the W film specific resistance.

FIG. 10 is a diagram showing the sputtering power dependence of the W film specific resistance.

FIG. 11 is an explanatory diagram of the coverage of a glue layer by collimated spatter.

[Fig.12] Illustration of collimator

FIG. 13 is an explanatory diagram of wide gap sputtering.

FIG. 14 is an explanatory diagram of RTA nitriding of Ti.

FIG. 15 is an explanatory diagram of heat treatment after opening a contact hole.

FIG. 16 is a cross-sectional view of a contact example when the glue layer is TiN / Ti.

FIG. 17 is a cross-sectional view of a contact example when the glue layer is W.

FIG. 18 is an explanatory diagram of W-plug formation.

FIG. 19 is a sectional view of a contact hole having a diameter of 0.4 μm or less.

[Fig. 20] An explanatory view of an isotropic shape by wet etching.

FIG. 21 is an explanatory diagram of WF ₆ flow rate dependence of deposition rate.

FIG. 22 is an explanatory diagram of conventional technology.

FIG. 23 is a cross-sectional view showing an example of BW wiring.

FIG. 24 is a cross-sectional view showing an example of forming a W-plug.

FIG. 25 is an explanatory diagram of nucleation during BW film formation.

FIG. 26 is an explanatory diagram of WF ₆ erosion during BW film formation.

FIG. 27 is an explanatory diagram of a problem caused by exposing Ti to WF ₆ .

FIG. 28 is a cross-sectional view when the glue layer is W.

29 is an explanatory view of a problem of patterning when the glue layer is W. FIG.

FIG. 30 is an explanatory diagram of a problem of BW wiring in a contact hole having a diameter of 0.4 μm or less.

[Explanation of symbols]

 1 Si substrate as semiconductor substrate 2 Insulating film 3 Ti film 4 TiN film as glue layer 4G W film as glue layer 5 Al film 6 Oxygen atoms 7 Al spikes 8 W film 8P W-plug 9 Wafer clamp ring 10 Resist film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 21/285 301 R 8932-4M

Claims (21)

[Claims] 1. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3), a titanium nitride film (4) and a tungsten film (8) are sequentially formed, and the film formation temperature of the titanium nitride film (4) is set to 4
A method of manufacturing a semiconductor device, wherein the temperature is set to 00 ° C. or higher. 2. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3), a titanium nitride film (4) and a tungsten film (8) are sequentially formed, and the film formation power of the titanium nitride film (4) is set to 1
A method of manufacturing a semiconductor device, characterized in that it is 0 W / cm ² or more. 3. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3), a titanium nitride film (4) and a tungsten film (8) are sequentially formed, and the nitrogen flow rate ratio at the time of forming the titanium nitride film (4) is 60% or more. And a method for manufacturing a semiconductor device. 4. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3) A titanium nitride film (4) and a tungsten film (8) are sequentially formed, and the titanium nitride film (4) is formed by a bias sputtering method. Method. 5. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3) A titanium nitride film (4) and a tungsten film (8) are sequentially formed, and the titanium nitride film (4) is formed by a collimated sputtering method. Manufacturing method. 6. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3), a titanium nitride film (4), and a tungsten film (8) are formed in this order, and the titanium nitride film (4) is widened by widening the gap between the target and the substrate to be grown to 100 mm or more. A method for manufacturing a semiconductor device, which comprises forming a film by a gap sputtering method. 7. An insulating film having a contact hole formed therein.
A titanium film is formed on a semiconductor substrate (1) on which the surface (2) is deposited.
(3), titanium nitride film (4) and tungsten film (8) are sequentially formed, and the titanium nitride film (4) is vapor-deposited (CV
A method for manufacturing a semiconductor device, characterized in that the film is formed by the method D). 8. An insulating film having a contact hole formed therein.
There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) on which the surface (2) is adhered.
A method of manufacturing a semiconductor device, wherein the film forming temperature of (4G) is 400 ° C. or higher. 9. An insulating film having a contact hole formed therein.
There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) on which the surface (2) is adhered.
A method of manufacturing a semiconductor device, wherein a gas pressure during film formation of (4G) is set to 7 mTorr or more. 10. An insulating film having a contact hole formed therein.
There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) on which the surface (2) is adhered.
A method of manufacturing a semiconductor device, characterized in that a film forming power of (4G) is set to ² to 4 W / cm ² or more. 11. An insulating film having a contact hole formed therein.
There is a step of sequentially forming a glue layer tungsten film (4G) and a tungsten film (8) on a semiconductor substrate (1) on which the surface (2) is adhered.
A method for manufacturing a semiconductor device, wherein the film formation of (4G) is performed by the method according to claim 4. 12. An insulating film having a contact hole formed therein.
On the semiconductor substrate (1) having the surface (2) deposited on its surface, there is a step of sequentially forming a glue layer (4) and a tungsten film (8), patterning the tungsten film (8), and then A method for manufacturing a semiconductor device, characterized in that the glue layer (4) is patterned using a reaction gas having a higher etching rate than the semiconductor substrate (1). 13. The method of manufacturing a semiconductor device according to claim 12, wherein the glue layer (4) is a laminated film in which a lower layer is titanium and an upper layer is titanium nitride. 14. The glue layer (4) is a semiconductor substrate.
14. The method for manufacturing a semiconductor device according to claim 13, wherein the tungsten film (8) is formed with the titanium nitride completely covering the titanium film. 15. An insulating film having a contact hole formed therein.
A glue layer (4) and a tungsten film (8) are sequentially formed on a semiconductor substrate (1) on which (2) is deposited on the surface, and the tungsten film (8) is etched back to remove the inside of the contact hole. 15. A method of manufacturing a semiconductor device, comprising the step of forming a tungsten-plug (9P) in the step of using a method according to claim 1. 16. An insulating film having a contact hole formed therein.
There is a step of sequentially forming a glue layer (4) and a tungsten film (8) on a semiconductor substrate (1) having the surface (2) deposited on the surface thereof, and the glue layer (4) is formed by a titanium film (3). The method for manufacturing a semiconductor device is characterized in that the surface of (1) is nitrided by a rapid heating method. 17. The method for manufacturing a semiconductor device according to claim 16, wherein the titanium film (3) is formed by a collimated sputtering method. 18. The method for manufacturing a semiconductor device according to claim 16, wherein the titanium film (3) is formed by a wide gap sputtering method in which the gap between the target and the substrate to be grown is expanded to 100 mm or more. 19. The insulating film (2) according to any one of claims 1 to 18, wherein a film containing at least a phosphosilicate glass film in a laminated structure thereof is used, and the film has a thickness of 75 before the contact hole is formed.
A method of manufacturing a semiconductor device, which comprises performing a heat treatment at 0 to 850 ° C. 20. The insulating film (2) according to any one of claims 1 to 18, wherein a film including at least a phosphosilicate glass film is used for the laminated structure, and isotropic etching and anisotropic etching are used for forming the contact hole. A method of manufacturing a semiconductor device, comprising: 21. The method for manufacturing a semiconductor device according to claim 1, wherein the tungsten film (8) is formed under a surface reaction rate-determining condition.